By default, new organizations are configured to disallow the forking of private and internal repositories.
If you allow forking of private and internal repositories at the organization level, you can also configure the ability to fork a specific private or internal repository. For more information, see "Managing the forking policy for your repository."
- GitHub Enterprise Server の右上隅にあるプロファイル写真をクリックし、 [自分の Organization] をクリックします。
- 組織の隣の [設定] をクリックします。
- [アクセス] で、 [メンバー特権] をクリックします。
- Under "Repository forking", select Allow forking of private and internal repositories.
- Click Save.